Grinding apparatus for meat-slicing machines and the like



MWh l 1927 v. H. M. BRuNsKoG ET Al- GRINDING APPARATUS FOR MEAT SLICING MACHINES AND THE LIKE Filed Dec; 2. i925 Patented Mar. 1, 1927.

UNITED STATES PATENT OFFICE.

VICTOR-HERBERT MAGNUS BRUNSKOG AND JOSEF AUGUST NORDIN, yOF STOCKHOLM, SWEDEN, ASSIGNORS TO AKTIEBOLAGET STILLE-WERNER,\ OF STOCKHOLM,

SWEDEN.

GRINDING APPARATUS FOR lVIEAT-SLICINGY MACHINES AND THE LIKE.

' Applcationpled December 2, 1925, Serial No. 72,805, and in Sweden October 24, 1925.

This invention relates to an apparatus for grinding the dish-knife of meat-slicing machines and the like.

Evidently, the saidv disk-knife must be ground comparatively often, because its edge always mustbe so sharp that the cutting operation is effected in wholly satisfactory manner. In order toy render the grinding convenient it has been previously proposed to combine a grinding apparatus with the meat-slicing machine. ing rollers are used, they are generally rotated either by their frictional contact with i the disk-knife or by means of a special driving device independent of the driving mechanism of the meat-slicing machine. In both cases, however, sufficient regard has not been paid to the fact, that there must exist a special relation between the velocity of the grinding vrollers and the velocity of the disk-knife, in order that the grinding operation may be effected rapidly, and effectively. Besides, sufficient stress has not been laid upon the adjusting of the pressure of the grinding member on the disk-knife with relation to the velocity.

According to this invention regard has been paid to the said velocity and pressure conditions. Thus, the grinding rollers are so arranged that the motion, imparted to same, is positively derived from one of the members of the driving mechanism of the disk-knife (for instance the shaft of the said knife), so that the rotary velocity of the rollers always has a certain, constant relation to the rotary velocity of dislcknife. Further, the grinding rollers, according to this invention, are so arranged, that the same are automatically moved into their operative position, yonly when they have gained a certain, predetermined velocity, in which position their pressure against the disk-knife is positively varied within certain limits according as the velocity of the disk-knife varies, so that the said pressure is increased, when the velocity is increased and vice versa.

A form of the invention is illustrated in the accompanying drawing, in which Fig. 1 is a side view of the grinding apparatus, Figs. 2 and 3 sections on the lines 2-2 and 3-3 respectively in Fig. 1, and Fig. 4 shows a detail.

1 is a frame, adapted to be fixed to the If grindframe (not shown) of the slicing machine in any suitable manner. The top part 2 of the said frame 1 is sleeve shaped and provided with a slot, extending unto its inner side, so that the sleeve 2 may be tightened on a sleeve 4:, Fig. 2, by'means of a'screw 3. The said sleeve 1 serves as a Ybearing for theY shaft 5 of the disk-knife 6, ball-bearings 7 being provided between the shaft and the sleeve, so that the disk-knife may be'rotated without any frictional resistance worth mentioning. A sprocket wheel 8 is fixed to the shaft 5 and rotated by means of a chain passing around wheel 8 and a vsecond sprocket wheel provided on another shaft, comprising the driving mechanism 'of the meat-slicing machine. The sprocket wheel last mentioned and its shaft are not shown in the drawing, because they are used in a plurality of meat-slicing machines and only serve to transmit motion to the disk-knife 6 by means of the chain 9 and the sprocket wheel 8. On the shaft 5 a toothed wheel 10 is fixed, with which a second toothed wheel 11 may be brought into engagement. The said toothed wheel 11 is fixed to or made integral with a shaft 12, which is movable and slidable in a sleeve or bearing 13, provided in the frame 1. A worm-wheel 111 is fixed to the said shaft 12 and meshes With a worm 15, provided on a shaft 16, rotatable in bearing in the frame 1. The said shaft 16 is enclosed for a portion of its length by a sleeve 17, which is fixed in the frame 1 and to which are fixed in an adjustable manner two arms 18 and 19 by means of set-screws 20 and 21 respectively, Fig. 1. Arms 18 and 19 carry sleeves 22 and 23, in which spindles 24 and 25 respectively are slidable but not rotatable'. Worm-wheels 27 and 28 are fixed on the sleeves 22 and 23 by means offscrews 26, said worm-wheels meshing with worm-wheels 29 and 30 respectively,

,fixed von the shaft 16, mentioned above.

Screws 26 extend through the sleeves 22 and 23 and into longitudinal grooves 31, provided in the spindles 24y and 25, so that the spindles are caused to rotate with the wormwheels 27 and 28 and the sleeves 22 andV 28, without the spindles being vprevented from moving longitudinally. A grinding roller 33 is fixed on the one end of the spindle 24 by means of a nut 32, and a helical sprinfr 34 is located on the rod `between the said roller and the sleeve 22. Said spring 34 tends to move the spindle to a certain initial position determined by the screw 26 and the groove 31. On the opposite end yof the spindle 24 a washer 36 or the like is fixed by means of a nut 35, inside which balls 37 are located bearing against a cup 38, made integral with the sleeve 22. As the rotary velocity has reached a certain amount, balls 37, evidently, will move outwards in the cup 38 acted upon by the centrifugal force, which results in the spindle 24 and thus also the grinding roller 33 being moved toward the frame 1 against the tension of the spring 34.

Spindle 25 is, in substantially the same manner as the spindle 24, provided with a grinding roller 39, which together with the said spindle may be moved longitudinally through the action of a helical sprino' 40 and balls 41. While the balls 37 move the spindle 24 inwards, balls 41 are so located, that they move the spindle 25 outwards, in consequence whereof the grinding rollers will be moved towards the disk-knife 6 extending freely between the same and act upon opposite sides of its edge, as explained below.

For bringing the toothed wheel 11 into engagement with the toothed wheel 10 a crank 42 is provided, Fig. 4, the hub 44 of which co-operates with a cam surface 43 or the like, so that the crank shaft 44 together with a plate 45 or the like fixed to the same is permitted to move longitudinally, as the crank is turned in a certain direction. Plate 45 engages a groove 46 cut in the worm-wheel 14, which thus together' with the shaft l2 and the toothed wheel 11 is caused to partake in the sliding movement of the crank shaft 44. A spring 47, Fig. 2, acts upon the shaft 12 and tends to move the same longitudinally in such direction, that the toot-hed wheel 11 is brought into engagement with thel toothed wheel l0, as the crank 42 is turned.

The grinding apparatus operates in the following manner. Vhen the disk-knife is to be ground, crank 42 is so turned, that the toot-hed wheel 11 is brought into engagement with the toothed wheel 10. Shaft 12 and worm-wheel 14 then are rotated, the rotary motion being transmitted to the worm 15 and shaft 16. Vorm-wheels 29 and 30 fixed on the shaft 16 rotate the worm-wheels 27 and 28 respectively iXed on the sleeves 22 and 23, whereby the spindles 24 and 25 and thus the grinding rollers 33 and 39 are rotated. If the rotary motion is sufliciently great, the balls 37 and 41 will cause the spindles 24 and 25 to slide axially against the action of the springs 34 and 40, as stated above, which results in the grinding rollers 33 and 39 being moved from an inactive position at some distance from the diskknife 6 nearer to the disk-knife at opposite sides of the same. As perceived from the above the velocities of the disk-knife 6 and he grinding rollers 33 and 39 are dependent upon the velocity, at which the slicing-machine is driven. Only when the velocity of the slicing machine has been increased to a certain amount, the grinding rollers will rub against the disk-knife. lt is of great importance for the gaining of an effective grinding action, that grinding takes place only when the disk-knife and the grinding rollers have gained a predetermined velocity. lf the velocity of the slicing machine is increased still more` the velocities of the disk-knife and the grinding rollers are in creased automatically, a constant relation between the velocity of the disk-'knife and the velocity of the grinding rollers being however maintained. As the velocity is increased also the pressure of the grinding rollers against the disk-knife is increased, which is of great importance.

As soon as the velocity is decreased to a certain value, the grinding rollers will leave the disk-knife acted upon by the springs 34 and 40. As the crank 42 is turned into such a direction, that the toothed wheel llris brought out of engagement with the toothed wheel 10, the grinding rollers, evidently, are uncoupled, so that their velocity decreases and the rollers after a short period are removed from the disk-knife.

The grinding surfaces of the rollers 33 and 39 are suitably shaped. In the drawing the grinding surface a of the roller 39 is turned inwards towards the frame 1, v'ihile the grinding surface of the roller 39-is turned outwards from the said frame. The initial position of the grinding rollers relatively to the disk-knife may be adjusted by loosening the screws 2O and 21 and moving the arms 18 and 19 into the necessary position. The members transmitting motion from the shaft 12 to the grinding rollers are enclosed in a casing providedin the frame 1 and closed by a lid 48, said members being thus protected against damage.

The form of execution shown in the drawing may, evidently be modified in many respects without exceeding the limits of the invention, the shown details may be regarded only as examples illustrating the principle' of the invention.

We claim:

1. Apparatus for grinding the disc-knife of a meat-slicing machine, comprising grinding members, said members being positively driven by the driving means of the machine, the rotary velocity of the grinding members having a constant relation to the rotary velocity of the disc-knife, and movable members subjected to the action of centrifugal force, said movable members being arranged to automatically move the grinding members into their grinding position only when la predetermined rotary velocity is attained.

2. Grinding apparatus as claimed in claim l, the members subjected to the act-ion of centrifugal force being arranged to automatically increase the pressure of the grinding members against the disc-knife when the velocity is increased.

3. Grinding apparatus as claimed in claim 1, the grinding members being fixed on slid able spindles moved axially by balls, and a spring associated with each of said spindles, said balls being caused to deviate from the radial movement by means of guides in which l@he balls tend to move when acted upon by the centrifugal force, thereby actuating the said spindles and move the same, said movement increasing the tension of said springs7 Which, when the centrifugal force is reduced or ceases, returns the spindles into their initial position.

In testimony whereof We have affixed our signatures.

VICTOR HERBERT MAGNUS BRUNSKOG. JOSEF AUGUST NORDIN. 

